Apparatus to treat esophageal sphincters

ABSTRACT

A sphincter treatment apparatus has an introducer means including a distal portion means. An expandable device means includes a plurality of arm means. Each arm means of the plurality has a distal section means and a proximal section means. Each of distal sections means of the arm means are coupled and each of the proximal sections means of the arm means are coupled to the introducer means distal portion means. The expandable device means is configured to at least partially dilate a sphincter in a deployed state. An energy delivery device means is introduceable from the introducer means into a selected site of the sphincter. The energy delivery device means is configured to deliver sufficient energy to reduce a frequency of relaxation of the sphincter.

RELATED APPLICATIONS

[0001] This application is a divisional of co-pending application Ser.No. 09/971,085, filed Oct. 4, 2001, which is a continuation ofapplication Ser. No. 09/032,092, filed Mar. 6, 1998, now abandoned.

FIELD OF THE INVENTION

[0002] This invention relates generally to an apparatus to treatsphincters, and more particularly to an apparatus to treat esophagealsphincters.

DESCRIPTION OF RELATED ART

[0003] Gastroesophageal reflux disease (GERD) is a commongastroesophageal disorder in which the stomach contents are ejected intothe lower esophagus due to a dysfunction of the lower esophagealsphincter (LES). These contents are highly acidic and potentiallyinjurious to the esophagus resulting in a number of possiblecomplications of varying medical severity. The reported incidence ofGERD in the U.S. is as high as 10% of the population (Castell DO;Johnston BT: Gastroesophageal Reflux Disease: Current Strategies ForPatient Management. Arch Fam Med, 5(4):221-7; (1996 April)).

[0004] Acute symptoms of GERD include heartburn, pulmonary disorders andchest pain. On a chronic basis, GERD subjects the esophagus to ulcerformation, or esophagitis and may result in more severe complicationsincluding esophageal obstruction, significant blood loss and perforationof the esophagus. Severe esophageal ulcerations occur in 20-30% ofpatients over age 65. Moreover, GERD causes adenocarcinoma, or cancer ofthe esophagus, which is increasing in incidence faster than any othercancer (Reynolds J C: Influence Of Pathophysiology, Severity, And CostOn The Medical Management Of Gastroesophageal Reflux Disease. Am JHealth Syst Pharm, 53(22 Suppl 3):S5-12 (1996 Nov. 15)).

[0005] Current drug therapy for GERD includes histamine receptorblockers which reduce stomach acid secretion and other drugs which maycompletely block stomach acid. However, while pharmacologic agents mayprovide short term relief, they do not address the underlying cause ofLES dysfunction.

[0006] Invasive procedures requiring percutaneous introduction ofinstrumentation into the abdomen exist for the surgical correction ofGERD. One such procedure, Nissen fundoplication, involves constructing anew “valve” to support the LES by wrapping the gastric fundus around thelower esophagus. Although the operation has a high rate of success, itis an open abdominal procedure with the usual risks of abdominal surgeryincluding: postoperative infection, herniation at the operative site,internal hemorrhage and perforation of the esophagus or of the cardia.In fact, a recent 10 year, 344 patient study reported the morbidity ratefor this procedure to be 17% and mortality 1% (Urschel, J D:Complications Of Antireflux Surgery, Am J Surg 166(1): 68-70; (1993July)). This rate of complication drives up both the medical cost andconvalescence period for the procedure and may exclude portions ofcertain patient populations (e.g., the elderly and immuno-compromised).

[0007] Efforts to perform Nissen fundoplication by less invasivetechniques have resulted in the development of laparoscopic Nissenfundoplication. Laparoscopic Nissen fundoplication, reported byDallemagne et al. Surgical Laparoscopy and Endoscopy, Vol. 1, No. 3,(1991), pp. 138-43 arid by Hindler et al. Surgical Laparoscopy andEndoscopy, Vol. 2, No. 3, (1992), pp. 265-272, involves essentially thesame steps as Nissen fundoplication with the exception that surgicalmanipulation is performed through a plurality of surgical cannulaintroduced using trocars inserted at various positions in the abdomen.

[0008] Another attempt to perform fundoplication by a less invasivetechnique is reported in U.S. Pat. No. 5,088,979. In this procedure, aninvagination device containing a plurality of needles is insertedtransorally into the esophagus with the needles in a retracted position.The needles are extended to engage the esophagus and fold the attachedesophagus beyond the gastroesophageal junction. A remotely operatedstapling device, introduced percutaneously through an operating channelin the stomach wall, is actuated to fasten the invaginatedgastroesophageal junction to the surrounding involuted stomach wall.

[0009] Yet another attempt to perform fundoplication by a less invasivetechnique is reported in U.S. Pat. No. 5,676,674. In this procedure,invagination is done by a jaw-like device and fastening of theinvaginated gastroesophageal junction to the fundus of the stomach isdone via a transoral approach using a remotely operated fasteningdevice, eliminating the need for an abdominal incision. However, thisprocedure is still traumatic to the LES and presents the postoperativerisks of gastroesophageal leaks, infection and foreign body reaction,the latter two sequela resulting when foreign materials such as surgicalstaples are implanted in the body.

[0010] While the methods reported above are less invasive than an openNissen fundoplication, some still involve making an incision into theabdomen and hence the increased morbidity and mortality risks andconvalescence period associated with abdominal surgery. Others incur theincreased risk of infection associated with placing foreign materialsinto the body. All involve trauma to LES and the risk of leaksdeveloping at the newly created gastroesophageal junction.

[0011] Besides the LES, there are other sphincters in the body which ifnot functionally properly can cause disease states or otherwiseadversely affect the lifestyle of the patient. Reduced muscle tone orotherwise aberrant relaxation of sphincters can result in a laxity oftightness disease states including, but not limited to, urinaryincontinence.

[0012] There is a need to provide an apparatus to treat a sphincter andreduce a frequency of sphincter relaxation. Another need exists for anapparatus to create controlled cell necrosis in a sphincter tissueunderlying a sphincter mucosal layer. Yet another need exists for anapparatus to create controlled cell necrosis in a sphincter and minimizeinjury to a mucosal layer of the sphincter. There is another need for anapparatus to controllably produce a lesion in a sphincter withoutcreating a permanent impairment of the sphincter's ability to achieve aphysiologically normal state of closure. Still a further need exists foran apparatus to create a tightening of a sphincter without permanentlydamaging anatomical structures near the sphincter. There is stillanother need for an apparatus to create controlled cell necrosis in alower esophageal sphincter to reduce a frequency of reflux of stomachcontents into an esophagus.

SUMMARY OF THE INVENTION

[0013] Accordingly, an object of the present invention is to provide anapparatus that reduces a frequency of sphincter relaxation.

[0014] Another object of the invention is to provide an apparatus tocreate controlled cell necrosis in a sphincter tissue underlying asphincter mucosal layer. Yet another object of the invention is toprovide an apparatus to create controlled cell necrosis in a sphincterand minimize injury to a mucosal layer of the sphincter.

[0015] A further object of the invention is to provide an apparatus tocontrollably produce a lesion in a sphincter without creating apermanent impairment of the sphincter's ability to achieve aphysiologically normal state of closure.

[0016] Still another object of the invention is to provide an apparatusto create a tightening of a sphincter without permanently damaginganatomical structures near the sphincter.

[0017] Another object of the invention is to provide an apparatus tocreate controlled cell necrosis in a lower esophageal sphincter toreduce a frequency of reflux of stomach contents into an esophagus.

[0018] These and other objects of the invention are provided in asphincter treatment apparatus within an introducer means including adistal portion means. An expandable device means includes a plurality ofarm means. Each arm means has a distal section means and a proximalsection means. Each of the distal section means of the arm means arecoupled and each of the proximal section means of the arm means arecoupled to the introducer means distal portion means. The expandabledevice means is configured to at least partially dilate a sphincter in adeployed state. An energy delivery device means is introduceable fromthe introducer means into a selected site of the sphincter. The energydelivery device means is configured to deliver sufficient energy toreduce a frequency of relaxation of the sphincter.

[0019] In another embodiment, an expandable device means is coupled toan introducer distal portion means. The expandable device means includesa first arm means with a proximal and distal section means and a secondarm means with proximal and distal section means. The first and secondarm distal portion means are coupled. The expandable device means isconfigured to at least partially dilate a sphincter in a deployed state.An energy delivery device means is coupled to the expandable devicemeans. The energy delivery device means is configured to deliversufficient energy to reduce a frequency of relaxation of the sphincterwhile minimizing cell necrosis of a mucosal layer of the sphincter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is an illustrated lateral view of the upper GI tractdepicting the position of the sphincter treatment apparatus of thepresent invention in the lower esophageal sphincter.

[0021]FIG. 2 is a lateral view of the present invention illustrating theintroducer, expansion device and energy delivery device.

[0022]FIG. 3 depicts a lateral view of an embodiment of the inventionthat illustrates the use of a sheath to introduce and deploy theexpansion device.

[0023]FIG. 4 illustrates a lateral view of the basket assembly used inan embodiment of the invention.

[0024]FIG. 5 is a lateral view of the basket assembly illustrating theplacement of struts on the basket assembly.

[0025]FIG. 6A is a lateral view of the junction between the basket armsand the introducer illustrating a lumen in the basket arm that can beused for the advancement of energy delivery devices.

[0026]FIG. 6B is a frontal view of a basket arm in an alternativeembodiment of the invention illustrating a track in the arm used toadvance the movable wire.

[0027]FIG. 7A is a cross-sectional view of a section of a basket arm andan energy delivery device illustrating stepped and tapered sections inthe basket arm apertures and energy delivery device.

[0028]FIG. 8A is a lateral view of the basket assembly illustrating theuse of the advancement member and introducer to position energy deliverydevices into the sphincter wall.

[0029]FIG. 8B is a lateral view of the basket assembly illustrating theuse of the advancement member and basket arms to position energydelivery devices into the sphincter wall.

[0030]FIG. 9 is a cross sectional view illustrating the use of a needleelectrode in combination with an angled aperture segment to select andmaintain a constant penetration angle into the sphincter wall.

[0031]FIG. 10 is a lateral view illustrating the placement of needleelectrodes into the sphincter wall by expansion of the basket assembly.

[0032]FIG. 11 is a lateral view illustrating the use of an insulationlayer on the needle electrode to protect an area of tissue from RFenergy.

[0033]FIG. 12 depicts the fluid source and flow path to deliver fluid totreatment site using the introducer.

[0034]FIG. 13 is a cross sectional view illustrating a visualizationdevice coupled to an embodiment of the invention.

[0035]FIG. 14 is an enlarged lateral view illustrating the placement ofsensors on/adjacent the energy delivery device and the coupling ofsensors to a feedback control system.

[0036]FIG. 15 is a flow chart illustrating a sphincter treatment methodusing the apparatus of the present invention.

[0037]FIG. 16 is a lateral view of sphincter smooth muscle tissueillustrating electrical foci and electrically conductive pathways forthe origination and conduction of aberrant electrical signals in thesmooth muscle of the lower esophageal sphincter or other tissue.

[0038]FIG. 17 is a lateral view of a sphincter wall illustrating theinfiltration of tissue healing cells into a lesion in the smooth tissueof a sphincter following treatment with the sphincter treatmentapparatus of the present invention.

[0039]FIG. 18 is a view similar to that of FIG. 17 illustratingshrinkage of the lesion site caused by cell infiltration.

[0040]FIG. 19 is a lateral view of the esophageal wall illustrating thepreferred placement of lesions in the smooth muscle layer of aesophageal sphincter.

[0041] FIGS. 20A-D are lateral views of the sphincter wall illustratingvarious patterns of lesions created by the apparatus of the presentinvention.

[0042]FIG. 21 depicts a block diagram of the feed back control systemthat can be used with an embodiment of the invention.

[0043]FIG. 22 depicts a block diagram of an analog amplifier, analogmultiplexer and microprocessor used with the feedback control system ofFIG. 21.

[0044]FIG. 23 depicts a block diagram of the operations performed in thefeedback control system depicted in FIG. 21.

DETAILED DESCRIPTION

[0045] Referring to FIGS. 1 and 2, one embodiment of a sphinctertreatment apparatus 10 delivers energy to a treatment site 12 to producelesions 14 in a sphincter 16, such as the lower esophageal sphincter(LES). In this embodiment, sphincter treatment apparatus 10 comprises aflexible elongate shaft 18, also called introducer 18, coupled to anexpansion device 20, in turn coupled with one or more energy deliverydevices 22. Introducer 18 has a distal extremity also called introducerend 19. Energy delivery devices 22 are configured to be coupled to apower source.

[0046] Expansion device 20 comprises a plurality of arms 24, withproximal and distal arms ends 25 and 26. Proximal arm ends 25 arecoupled to introducer end 19. Expansion device 20 has a centrallongitudinal axis 28 and is moveable between contracted andexpanded/deployed states substantially there along. Expansion device 20is configured to be positionable in a sphincter 16 (such as the LES) oradjacent anatomical structure (such as the cardia of the stomach) and isfurther configured to partially dilate sphincter 16 when in the deployedstate. Energy delivery devices 22 are configured to be introduceablefrom introducer 18 and to contact and/or penetrate a targeted treatmentsite 12 in a sphincter wall 30 or adjoining anatomical structure. Theyare further configured to deliver energy to treatment site 12.

[0047] Referring now to FIG. 2, introducer 18 is configured to becoupled to expansion device 20 and has sufficient length to positionexpansion device 20 in the LES and/or stomach using a transoralapproach. Typical lengths for introducer 18 include a range of 40-180cm. Introducer 18 may be circular or oval in cross section. Also,introducer 18 may be flexible, articulated, coil-reinforced, orsteerable, or any combination thereof. Suitable materials for introducer18 include polyethylenes, polyurethanes, silicones and otherbiocompatible polymers known to those skilled in the art. Introducer 18may also be coated with a lubricious coating as is well known to thoseskilled in the art.

[0048] Introducer 18 may have one or more lumens 32, that extend thefull length of introducer 18, or only a portion thereof. Lumens 32 maybe used as paths for the delivery of fluids and gases, as well asproviding channels for cables, catheters, guide wires, pull wires,insulated wires, and optical fibers.

[0049] In another embodiment of the invention depicted in FIG. 3, anintroduction member 34, also called a sheath 34, is used to introducesphincter treatment apparatus 10 into the LES. Sheath 34 can alsofunction as a sheath for expansion device 20 to keep it in a nondeployedor contracted state during introduction into the LES. To facilitate thisfunction, sheath 34 contains a sheath lumen 36 of sufficient innerdiameter to allow free movement of sphincter treatment apparatus 10within sheath lumen 36. Sheath 34, sheath lumen 36 and sphinctertreatment apparatus 10 are configured to allow expansion device 20 to gofrom a contracted state to an expanded state and vice versa by either i)the retraction or advancement of sheath 34, or ii) the advancement orwithdrawal of sphincter treatment apparatus 10. Sheath 34 may beflexible, articulated, coil-reinforced or steerable, or any combinationthereof Suitable materials for sheath 34 include polyethylenes,polyurethanes, silicones, polytetrafluoroethylenes and otherbiocompatible polymers known to those skilled in the art. Typicaldiameters for sheath lumen 36 include 0.1 to 2 inches, while typicallengths include 40-180 cms.

[0050] Referring now to FIG. 4, in another embodiment of the presentinvention, expansion device 20 comprises one or more elongated arms 24that are joined at their proximal ends 25 and distal ends 26 to form abasket assembly 38. Proximal arm end 25 is attached to a supportingstructure, which can be distal end 19 of introducer 18 or a proximal cap40. Likewise, distal arm end 26 is also attached to a supportingstructure which can be a distal basket-cap 42 or introducer 18. Arms 24are of a sufficient number, two or more, to sufficiently open and effacethe folds of sphincter 16 to allow treatment with sphincter treatmentapparatus 10, while preventing herniation of sphincter wall 30 into thespaces 44 between arms 24.

[0051] Arms 24 may form a variety of geometric shapes including, curved,rectangular, trapezoidal, triangular, or any combination thereof Also,arms 24 can have an outwardly bowed shaped memory for expanding basketassembly 38 into engagement with sphincter wall 30. Arms 24 may bepreshaped at time of manufacture or shaped by the physician. Arms 24 canhave a variety of cross sectional geometries including, circular,rectangular and crescent-shaped. The circumferential spacing of arms 24can be symmetrical or asymmetrical with respect to a circumferencearound longitudinal axis 28. Suitable materials for arms 24 includespring steel, stainless steel, superelastic shape memory metals such asnitinol, or stiff shaft plastic tubing as is well known to those skilledin the art. Arms 24 may also be color-coded to facilitate theiridentification via visual medical imaging methods and equipment, such asendoscopic methods, which are well known to those skilled in the art.

[0052] In another embodiment of the invention depicted in FIG. 5, asupporting member 46 is attached to two or more arms 24. Supportingmember 46, also called strut 46, can be attached to arms 24 along acircumference of basket assembly 38. Strut 46 may also contain apertures50 in one or more places that extend through strut 46 to arm 24 as willbe discussed herein. The cross sectional geometry of strut 46 can berectangular, circular or crescent-shaped. Suitable materials for strut46 include spring steel, stainless steel, superelastic shape memorymetals such as nitinol, or stiff shaft plastic tubing as is well knownto those skilled in the art.

[0053] Referring now to FIG. 6A, arms 24 may be solid or hollow with acontinuous arm lumen 48 that may be coupled with introducer lumens 32.Also arms 24 may have one or more apertures 50 that may coupled to armlumen 48. Coupled lumens 32 and 48, and apertures 50 provide a path forthe delivery of a fluid or energy delivery device 22 from introducer 18to the surface or interior of sphincter wall 30. As shown in FIG. 6B,arms 24 may also have a partially open channel 52, also called a track52, that functions as a guide track for the travel of an advancementmember (discussed herein) and/or energy delivery device 22 that permitthe controlled placement of energy delivery devices 22 at or intosphincter wall 30. Referring now to FIG. 7, apertures 50 may havetapered sections 54 and/or stepped sections 56 in all or part of theirlength, that are used to control the penetration depth of energydelivery devices 22 into sphincter wall 30 as will be discussed herein.Energy delivery devices 22 may have similar tapered sections 54′ and/orstepped sections 56′.

[0054] Referring now to FIGS. 8A and 8B, in another embodiment of theinvention, energy delivery devices 22 can be coupled to an energy devicedelivery member 57, also called an advancement member 57. Advancementmember 57 can be an insulated wire, an insulated guide wire, aplastic-coated stainless steel hypotube with internal wiring or aplastic catheter with internal wiring as is well known to those skilledin the art. Advancement member 57 is configured to be able to introduceenergy delivery device 22 into sphincter wall 30 via introducer 18 (seeFIG. 8A) or basket assembly 38 as will be discussed herein (see FIG.8B). Advancement member 57 is of sufficient length to position energydelivery device 22 in the LES and/or stomach using a transoral approach.Typical lengths for advancement member 57 include a range of 40-180 cms.

[0055] In another embodiment of the invention depicted in FIG. 9, energydelivery device 22 has a distal portion 58 that is configured topenetrate sphincter wall 30 with a minimum amount of tearing of themucosal and submucosal layers 60 and 62 of sphincter 16. This isfacilitated by maintaining a constant angle of penetration 64, alsocalled penetration angle 64, of distal portion 58 into sphincter wall 30during the time that energy delivery device 22 is advanced intosphincter wall 30. The typical range for penetration angle 64 liesbetween 1 and 90°. This can be accomplished through the use of a needle58′ for distal energy delivery device portion 58, coupled with an angledaperture segment 50′ having a preselected penetration angle 64. Needle58′ is of sufficient sharpness and length to penetrate into the smoothmuscle of sphincter wall 30. In a further embodiment, needle 58′ can bea needle electrode 58. Distal portion 58, including needle 58′ andneedle electrode 58 can also be stepped or tapered to enable control ofenergy delivery device (see FIG. 7). Suitable materials for needle 58′and needle electrodes 58″ include 304 stainless steel and other metalsknown to those skilled in the art.

[0056] In another embodiment of the invention, energy delivery device 22is coupled to arm 24. As shown in FIG. 10, this can be accomplished byattaching needle 58′ to arm 24. When sphincter treatment apparatus 10 isproperly positioned at the treatment site 12, needles 58′ are deployedby expansion of basket assembly 38, resulting in the protrusion ofneedle 58′ into the smooth muscle tissue of sphincter wall 30 (see FIG.10). Referring back to FIG. 9, coupling can also be accomplished byemploying arm 24 to introduce energy delivery device 22 into sphincterwall 30 via use of arm lumen 48.

[0057] Turning now to a discussion of energy delivery, suitable powersources and energy delivery devices 22 that can be employed in one ormore embodiments of the invention include or more of the following: (i)a radio-frequency (RF) source coupled to an RF electrode, (ii) acoherent source of light coupled to an optical fiber, (iii) anincoherent light source coupled to an optical fiber, (iv) a heated fluidcoupled to a catheter with a closed channel configured to receive theheated fluid, (v) a heated fluid coupled to a catheter with an openchannel configured to receive the heated fluid, (vi) a cooled fluidcoupled to a catheter with a closed channel configured to receive thecooled fluid, (vii) a cooled fluid coupled to a catheter with an openchannel configured to receive the cooled fluid, (viii) a cryogenicfluid, (ix) a resistive heating source, (x) a microwave source providingenergy from 915 MHz to 2.45 GHz and coupled to a microwave antenna, or(xi) an ultrasound power source coupled to an ultrasound emitter,wherein the ultrasound power source produces energy in the range of 300KHZ to 3 GHz. For ease of discussion for the remainder of thisapplication, the power source utilized is an RF source and energydelivery device 22 is one or more RF electrodes 66, also described aselectrodes 66. However, all of the other herein mentioned power sourcesand energy delivery devices are equally applicable to sphinctertreatment apparatus 10.

[0058] For the case of RF energy, RF electrode 66 may be operated ineither bipolar or monopolar mode with a ground pad electrode. In amonopolar mode of delivering RF energy, a single electrode 66 is used incombination with an indifferent electrode patch that is applied to thebody to form the other electrical contact and complete an electricalcircuit. Bipolar operation is possible when two or more electrodes 66are used. Multiple electrodes 66 may be used. These electrodes may becooled as described herein. Electrodes 66 can be attached to advancementmember 57 by the use of soldering methods which are well known to thoseskilled in the art.

[0059] Referring now to FIG. 11, RF electrodes 66 can have an insulatinglayer 68, covering an insulated segment 70 except for an exposed segment72. For purposes of this disclosure, an insulator or insulation layer isa barrier to either thermal or electromagnetic energy flow including RFenergy flow. Insulated segment 70 is of sufficient length to extend intosphincter wall 30 and minimize the transmission of RF energy to aprotected site 74 near or adjacent to insulated segment 70. Typicallengths for insulated segment 70 include, but are not limited to, 1-4mm. Suitable materials for insulating layer 68 include electricallyinsulating plastics and other materials well known to those skilled inthe art.

[0060] In another embodiment of the invention, the depth of penetrationof energy delivery device 22 into sphincter wall 30 is controllable.This can be accomplished by the selection and control of the dimensionalrelationships (e.g. the amount of clearance between inner and outerdiameters) of energy delivery devices 22 and/or advancement member 57 toone or more of the following elements: arm lumen 48, apertures 50 andtrack 52. Control of penetration depth can also be accomplished throughthe use of tapered and/or stepped sections in one or more of thepreceding elements as is discussed herein. In another embodiment,penetration depth control can be accomplished by the use of one or moreof a variety of positional control means, known to those skilled in theart, that are coupled to sphincter treatment apparatus 10. Suchpositional control means include stepper motor systems, indexingmechanisms and micromanipulators.

[0061] Referring now to FIG. 12, in another embodiment of the invention,fluid can be delivered to treatment site 12 via introducer 18. This isaccomplished by the coupling of introducer 18 to a fluid source 76 viaintroducer lumen 32.

[0062] Referring now to FIG. 13, another embodiment of sphinctertreatment apparatus 10 includes a visualization device 78 coupled tointroducer 18. Visualization device 78 can include a combination of oneor more of the following: a viewing scope, an expanded eyepiece, fiberoptics (both imaging and illuminating fibers), video imaging devices andthe like.

[0063] As shown in FIG. 14, one or more sensors 80 may be positionedadjacent to or on electrode 66 for sensing the physical properties ofsphincter tissue at treatment site 12. Sensors 80 permit accuratedetermination of the physical properties of sphincter wall 30 at anelectrode-tissue interface 82. Such physical properties includetemperature, electrical conductivity, electrical capacitance, thermalconductivity, density, thickness, strength, elasticity, moisturecontent, optical reflectance, optical transmittance, optical absorptionacoustical impedance and acoustical absorption. Sensors 80 can bepositioned at any position on expansion device 20, electrode 66 orbasket assembly 38. Suitable sensors that may be used for sensor 80include: thermocouples, fiber optics, photomultipliers, resistive wires,thermocouple IR detectors, thin film sensors, anemometric sensors andultrasound sensors. Sensor 80 can be coupled to a feedback controlsystem 84, described herein. The coupling of sensor 80 to feedbackcontrol system 84 can be used to regulate the delivery of energy, fluidsand gases to one or more of the following locations: treatment site 12,sphincter wall 30, and electrode tissue interface 82.

[0064]FIG. 15 is a flow chart illustrating a method for using sphinctertreatment apparatus 10. First, sphincter treatment apparatus 10 isintroduced into the esophagus under local anesthesia and positioned attreatment site 12. Sphincter treatment apparatus 10 can be introducedinto the esophagus by itself or through a lumen in an endoscope (notshown), such as disclosed in U.S. Pat. Nos. 5,448,990 and 5,275,608,incorporated herein by reference, or a similar esophageal access deviceknown to those skilled in the art. Basket assembly 38 is expanded asdescribed herein. This serves to temporarily dilate the LES sufficientlyto efface all or a portion of the folds of the LES. In an alternativeembodiment, esophageal dilation and subsequent LES fold effacement canbe accomplished by insufflation of the esophagus (a known technique)using gas introduced into the esophagus through introducer lumen 32, anendoscope, or others esophageal access devices known to those skilled inthe art. Once treatment is completed, basket assembly 38 is returned toits predeployed or contracted state and sphincter treatment apparatus 10is withdrawn from the esophagus. This results in the LES returning toapproximately its pretreatment state and diameter. It will beappreciated that the above procedure is applicable in whole or part tothe treatment of other sphincters in the body.

[0065] The diagnostic phase of the procedure then begins and can beperformed using a variety of diagnostic methods known to those skilledin the art including the following: (i) visualization of the interiorsurface of the esophagus via an endoscope or other viewing apparatusinserted into the esophagus, (ii) visualization of the interiormorphology of the esophageal wall using ultrasonography to establish abaseline for the tissue to be treated, (iii) impedance measurement todetermine the electrical conductivity between esophageal mucosal andsubmucosal layers 60 and 62 and sphincter treatment apparatus 10, and(iv) measurement and surface mapping of electropotential signals of theLES and surrounding anatomical structures during varying time intervalswhich may include such events as depolarization, contraction andrepolarization of gastroesophageal smooth muscle tissue. This lattertechnique is done to determine target treatment sites 12 in the LES oradjoining anatomical structures that are acting as electrical foci 107or electrically conductive pathways 109 for abnormal or inappropriatepolarization and relaxation of the smooth muscle of the LES (Refer toFIG. 16).

[0066] After diagnosis, the treatment phase of the procedure begins. Inthis phase of the procedure, the delivery of energy to treatment site 12can be conducted under feedback control, manually or by a combination ofboth. Feedback control (described herein) enables sphincter treatmentapparatus 10 to be positioned and retained in the esophagus duringtreatment with minimal attention by the physician. Electrodes 66 can bemultiplexed in order to treat the entire targeted treatment site 12 oronly a portion thereof. Feedback can be included and is achieved by theuse of one or more of the following methods: (i) visualization, (ii)impedance measurement, (iii) ultrasonography, (iv) temperaturemeasurement; and, (v) contractile force measurement via manometry. Thefeedback mechanism permits the selected on-off switching of differentelectrodes 66 in a desired pattern, which can be sequential from oneelectrode 66 to an adjacent electrode 66, or can jump around betweennon-adjacent electrodes 66. Individual electrodes 66 are multiplexed andvolumetrically controlled by a controller.

[0067] The area and magnitude of cell injury in the LES or sphincter 16can vary. However, it is desirable to deliver sufficient energy to thetargeted treatment site 12 to be able to achieve tissue temperatures inthe range of 55-95° C. and produce lesions 14 at depths ranging from 1-4mms from the interior surface of the LES or sphincter wall 30. Typicalenergies delivered to the esophageal or stomach wall include, but arenot limited to, a range between 100 and 50,000 joules per electrode 66.It is also desirable to deliver sufficient energy such that resultinglesions 14 have a sufficient magnitude and area of cell injury to causean infiltration of lesion 14 by fibroblasts 110, myofibroblasts 112,macrophages 114 and other cells involved in the tissue healing process(refer to FIG. 17). As shown in FIG. 18, these cells cause a contractionof tissue around lesion 14, decreasing its volume and/or altering thebiomechanical properties at lesion 14 so as to result in a tightening ofthe LES or sphincter 16. These changes are reflected in transformedlesion 141. The diameter of lesions 14 can vary between 0.1 to 4 mm. Itis preferable that lesions 14 are less than 4 mmns in less than 4 mms indiameter in order to reduce the risk of thermal damage to mucosal andsubmucosal layers 60 and 62. In one embodiment, a 2 mm diameter lesion14 centered in the wall of the smooth muscle provides a 1 mm buffer zoneon either side of lesion 14 to prevent damage to mucosal and submucosallayers 60 and 62 and the adventitia (not shown), while still allowingfor cell infiltration and subsequent sphincter tightening onapproximately 50% of the thickness of the wall of the smooth muscle(refer to FIG. 19).

[0068] It is desirable that lesions 14 are predominantly located in thesmooth muscle layer of selected sphincter 16 at the depths ranging from1 to 4 mm from the interior surface of sphincter wall 30. However,lesions 14 can vary both in number and position within sphincter wall30. It may be desirable to produce a pattern of multiple lesions 14within the sphincter smooth muscle tissue in order to obtain a selecteddegree of tightening of the LES or other sphincter 16. Typical lesionpatterns shown in FIGS. 20 A-D include, but are not limited to, (i) aconcentric circle of lesions 14 all at fixed depth in the smooth musclelayer evenly spaced along the radial axis of sphincter 16, (ii) a wavyor folded circle of lesions 14 at varying depths in the smooth musclelayer evenly spaced along the radial axis of sphincter 16, (iii) lesions14 randomly distributed at varying depths in the smooth muscle, butevenly spaced in a radial direction and, (iv) an eccentric pattern oflesions 14 in one or more radial locations in the smooth muscle wall.Accordingly, the depth of RF and thermal energy penetration intosphincter 16 is controlled and selectable. The selective application ofenergy to sphincter 16 may be the even delivery of RF energy to theentire targeted treatment site 12, a portion of it, or applyingdifferent amounts of RF energy to different sites depending on thecondition of sphincter 16. If desired, the area of cell injury can besubstantially the same for every treatment event.

[0069] A second diagnostic phase may be included after the treatment iscompleted. This provides an indication of LES tightening treatmentsuccess, and whether or not a second phase of treatment, to all or onlya portion of the esophagus, now or at some later time, should beconducted. The second diagnostic phase is accomplished through one ormore of the following methods: (i) visualization, (ii) measuringimpedance, (iii) ultrasonography, (iv) temperature measurement, or (v)measurement of LES tension and contractile force via manometry.

[0070] In one embodiment of the invention, sensor 80 is coupled to anopen or closed loop feedback control system 84. Referring now to FIG.21, an open or closed loop feedback system 84 couples sensor 80, nowdescribed as sensor 346, to an energy source 392. In this embodiment, anenergy delivery device 314 is one or more RF electrodes 314; however, invarious other embodiments, energy delivery device 314 may include othersdescribed herein. Similarly, in this embodiment, sensor 346 sensestemperature, but in various other embodiments, sensor 346 may senseother physical properties described herein.

[0071] The temperature of the tissue, or of RF electrode 314, ismonitored, and the output power of energy source 392 adjustedaccordingly. The physician can, if desired, override the closed or openloop system 84. A microprocessor 394 can be included and incorporated inthe closed or open loop system to switch power on and off, as well asmodulate the power. The closed loop system 84 utilizes microprocessor394 to serve as a controller, monitor the temperature, adjust the RFpower, analyze the result, refeed the result, and then modulate thepower.

[0072] With the use of sensor 346 and feedback control system 84, tissueadjacent to RF electrode 314 can be maintained at a desired temperaturefor a selected period of time without causing a shut down of the powercircuit to electrode 314 due to the development of excessive electricalimpedance at electrode 314 or adjacent tissue. Each RF electrode 314 isconnected to resources which generate an independent output. The outputmaintains a selected energy at RF electrode 314 for a selected length oftime.

[0073] Current delivered through RF electrode 314 is measured by currentsensor 396. Voltage is measured by voltage sensor 398. Impedance andpower are then calculated at power and impedance calculation device 400.These values can then be displayed at user interface and display 402.Signals representative of power and impedance values are received by acontroller 404.

[0074] A control signal is generated by controller 404 that isproportional to the difference between an actual measured value, and adesired value. The control signal is used by power circuits 406 toadjust the power output an appropriate amount in order to maintain thedesired power delivered at respective RF electrodes 314.

[0075] In a similar manner, temperatures detected at sensor 346 providefeedback for maintaining a selected power. Temperature at sensor 346 isused as a safety means to interrupt the delivery of power when maximumpre-set temperatures are exceeded. The actual temperatures are measuredat temperature measurement device 408, and the temperatures aredisplayed at user interface and display 402. A control signal isgenerated by controller 404 that is proportional to the differencebetween an actual measured temperature and a desired temperature. Thecontrol signal is used by power circuits 406 to adjust the power outputan appropriate amount in order to maintain the desired temperaturedelivered at the sensor 346. A multiplexer can be included to measurecurrent, voltage and temperature, at the sensor 346, and energy can bedelivered to RF electrode 314 in monopolar or bipolar fashion.

[0076] Controller 404 can be a digital or analog controller, or acomputer with software. When controller 404 is a computer it can includea CPU coupled through a system bus. This system can include a keyboard,a disk drive, or other non-volatile memory systems, a display, and otherperipherals, as are known in the art. Also coupled to the bus is aprogram memory and a data memory.

[0077] User interface and display 402 includes operator controls and adisplay. Controller 404 can be coupled to imaging systems including, butnot limited to, ultrasound, CT scanners, X-ray, MRI, mammographic X-rayand the like. Further, direct visualization and tactile imaging can beutilized.

[0078] The output of current sensor 396 and voltage sensor 398 are usedby controller 404 to maintain a selected power level at RF electrode314. The amount of RF energy delivered controls the amount of power. Aprofile of the power delivered to electrode 314 can be incorporated incontroller 404 and a preset amount of energy to be delivered may also beprofiled.

[0079] Circuitry, software and feedback to controller 404 result inprocess control, the maintenance of the selected power setting which isindependent of changes in voltage or current, and is used to change thefollowing process variables: (i) the selected power setting, (ii) theduty cycle (e.g., on-off time), (iii) bipolar or monopolar energydelivery; and, (iv) fluid delivery, including flow rate and pressure.These process variables are controlled and varied, while maintaining thedesired delivery of power independent of changes in voltage or current,based on temperatures monitored at sensor 346.

[0080] Referring now to FIG. 22, current sensor 396 and voltage sensor398 are connected to the input of an analog amplifier 410. Analogamplifier 410 can be a conventional differential amplifier circuit foruse with sensor 346. The output of analog amplifier 410 is sequentiallyconnected by an analog multiplexer 412 to the input of A/D converter414. The output of analog amplifier 410 is a voltage which representsthe respective sensed temperatures. Digitized amplifier output voltagesare supplied by A/D converter 414 to microprocessor 394. Microprocessor394 may be a type 68HCII available from Motorola. However, it will beappreciated that any suitable microprocessor or general purpose digitalor analog computer can be used to calculate impedance or temperature.

[0081] Microprocessor 394 sequentially receives and stores digitalrepresentations of impedance and temperature. Each digital valuereceived by microprocessor 394 corresponds to different temperatures andimpedances.

[0082] Calculated power and impedance values can be indicated on userinterface and display 402. Alternatively, or in addition to thenumerical indication of power or impedance, calculated impedance andpower values can be compared by microprocessor 394 to power andimpedance limits. When the values exceed predetermined power orimpedance values, a warning can be given on user interface and display402, and additionally, the delivery of RF energy can be reduced,modified or interrupted. A control signal from microprocessor 394 canmodify the power level supplied by energy source 392.

[0083]FIG. 23 illustrates a block diagram of a temperature and impedancefeedback system that can be used to control the delivery of energy totissue site 416 by energy source 392 and the delivery of a coolingmedium to electrode 314 and/or tissue site 416 by flow regulator 418.Energy is delivered to RF electrode 314 by energy source 392, andapplied to tissue site 416. A monitor 420 ascertains tissue impedance,based on the energy delivered to tissue, and compares the measuredimpedance value to a set value. If measured impedance is withinacceptable limits, energy continues to be applied to the tissue. Howeverif the measured impedance exceeds the set value, a disabling signal 422is transmitted to energy source 392, ceasing further delivery of energyto RF electrode 314.

[0084] The control of the delivery of cooling medium to electrode 314and/or tissue site 416 is done in the following manner. During theapplication of energy, temperature measurement device 408 measures thetemperature of tissue site 416 and/or RF electrode 314. A comparator 424receives a signal representative of the measured temperature andcompares this value to a pre-set signal representative of the desiredtemperature. If the measured temperature has not exceeded the desiredtemperature, comparator 424 sends a signal to flow regulator 418 tomaintain the cooling solution flow rate at its existing level. Howeverif the tissue temperature is too high, comparator 424 sends a signal toa flow regulator 418 (connected to an electronically controlledmicropump, not shown) representing a need for an increased coolingsolution flow rate.

[0085] The foregoing description of a preferred embodiment of theinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in this art. Itis intended that the scope of the invention be defined by the followingclaims and their equivalents.

We claim:
 1. A sphincter treatment apparatus comprising: an introducerhaving an introducer lumen, an expandable device coupled to theintroducer, the expandable device including a first arm with a proximalsection and a distal section and a second arm with a proximal sectionand a distal section, the first and second arm distal sections beingcoupled, at least one of the first and second arms including an armlumen coupled in fluid communication with the introducer lumen fordelivery of a fluid, the expandable device being configured to at leastpartially dilate a sphincter in a deployed state, and an energy deliverydevice coupled to the expandable device.
 2. An apparatus as in claim 1wherein at least a portion of the energy delivery device is advanceableinto the sphincter.
 3. An apparatus as in claim 1 wherein the at leastone of the first and second arms includes an aperture coupled to theintroducer lumen and adapted to provide a path for delivery of the fluidfrom the introducer.
 4. An apparatus as in claim 3 wherein the fluid iscooling fluid.
 5. A method of treating a sphincter comprising: providingan introducer, the introducer carrying an expandable device, providingan energy delivery device coupled to the expandable device, deployingthe introducer to a targeted tissue site at or near a sphincter,expanding the expandable device to at least partially dilate thesphincter, delivering energy from the energy delivery device to thetargeted tissue site, and delivering a cooling fluid from theintroducer.
 6. A method as in claim 5 wherein the expandable deviceincludes a first arm with a proximal section and a distal section and asecond arm with a proximal section and a distal section, the first andsecond arm distal sections being coupled.
 7. A method as in claim 6wherein at least one of the first and second arms includes a lumen.
 8. Amethod as in claim 5 wherein the introducer includes a lumen.
 9. Amethod as in claim 5 wherein the cooling fluid is delivered at a sensedflow rate, further comprising, measuring the temperature of at least oneof the tissue site and the energy delivery device, and comparing themeasured temperature to a pre-set desired temperature.
 10. A method asin claim 9, further comprising maintaining the flow rate if the measuredtemperature does not exceed the desired temperature.
 11. A method as inclaim 9, further comprising increasing the flow rate if the measuredtemperature exceeds the desired temperature.